(a) Field of the Invention
The invention relates to a device, particularly to a voltage control oscillator and control method thereof.
(b) Description of the Related Art
Applications, like PCIE (Peripheral Component Interconnection EXPRESS), universal serial bus (such as USB 3.0), etc., may use a transceiver to receive or transmit data. The transceiver usually comprises various circuit modules, such as a phase lock loop (PLL), a clock data recovery (CDR) circuit, etc.
Further a clock data recovery (CDR) circuit usually includes a voltage control oscillator (VCO). In the system design, the voltage control oscillator needs to have a broader frequency range and a smaller KVCO so that the clock data recovery circuit can lock frequency in a broader frequency range and output a signal with lowered jitter. However, the designed smaller KVCO may result in difficulty of covering larger temperature or voltage variation after the clock data recovery circuit locks frequency so as to cause the application limitation.